So i know this thread is over a year old but I am actually currently going through the exact same problem, when preparing campaign I had no issues at all, started campaign with players and first scene went smoothly, ended session and loaded into to continue building onto existing save file, stuck infinitely loading into next scene, I have tried creating a default scene, loading into a scene already built during prepare, I uninstalled and reinstalled the entire game, I have changed my mod list around... Nothing works. I have no idea what i need to do to fix this